Apart from natural silk, textile threads composed of fibres containing protein of which there is general knowledge include a certain type of lactose composite silk which was disclosed in Japan in “Fibrous Protein Chemistry” and which was based on protein extracted from cow's milk. This protein was mixed with acrylonitrile to form a composite lactose silk. Due to the use of animal proteins as raw material in this type of composite silk this product was extremely expensive.
In order to make the best use of available resources, and in order to reduce the cost of composite silk whilst ensuring that products retain acceptable characteristics, the present inventor has already disclosed a certain type of phytoprotein composite silk and the method of its manufacture in Chinese patent 99116636.1, and this type of composite silk possessed characteristics similar to silk; the phytoprotein content of this type of composite silk was between 23-55 of the overall content. However, after further research and trial-production by the present inventor, it was discovered that there was a still greater potential for development of composite silk based on phytoprotein; the synthetic fibres thus produced exhibited even better properties than current composite silks, for instance in terms of breathability. In addition, due to the relatively long duration of the production cycle involved in the manufacturing method outlined by the above-mentioned patent, the yield was relatively low.